Structured Partial Predictability in Non-Concatenative Morphology: The Case of Tashlhiyt Berber

John Alderete, Hamza Sellami


Abstract
Non-concatenative morphology poses a persistent challenge for NLP, yet structured quantitative resources for Amazigh (Berber) languages remain scarce. We present the first large-scale computational study of Tashlhiyt Berber plural formation, drawing on a richly annotated dataset of 1,185 noun paradigms with phonological, morphological and semantic features. We decompose the plural system into macro-level word-formation strategies and micro-level stem mutations, and evaluate predictability across ten target domains using linguistic feature models, N-gram baselines, and Bi-LSTM neural models. Results reveal a structured split: linguistic features decisively outperform neural models on systematic macro-level strategies (e.g., +44.5pp F1), while Bi-LSTMs better capture lexically idiosyncratic patterns. Rather than supporting a categorical rule/memory divide, this complementarity reveals gradient layers of regularity within a single morphological system. These findings demonstrate the value of linguistically informed annotation for probing morphological complexity in low-resource, typologically diverse languages. All data, code, and models are publicly available.
Anthology ID:
2026.slide-1.11
Volume:
Proceedings of the Workshop on Structured Linguistic Data and Evaluation (SLiDE)
Month:
May
Year:
2026
Address:
Palma de Mallorca, Spain
Editors:
Erhard Hinrichs, Joakim Nivre, Petya Osenova, James Pustejovsky, Claus Zinn
Venues:
SLiDE | WS
SIG:
Publisher:
ELRA Language Resources Association (ELRA)
Note:
Pages:
124–135
Language:
External URL:
https://lrec.elra.info/lrec2026-ws-slide-11
DOI:
10.63317/32kvdo5hchjo
Bibkey:
Cite (ACL):
John Alderete and Hamza Sellami. 2026. Structured Partial Predictability in Non-Concatenative Morphology: The Case of Tashlhiyt Berber. In Proceedings of the Workshop on Structured Linguistic Data and Evaluation (SLiDE), pages 124–135, Palma de Mallorca, Spain. ELRA Language Resources Association (ELRA).
Cite (Informal):
Structured Partial Predictability in Non-Concatenative Morphology: The Case of Tashlhiyt Berber (Alderete & Sellami, SLiDE 2026)
Copy Citation: